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Shell variable Use a fixed string to represent unfixed content Type of variable Custom variable Defining variables: variable name = variable value. Variable names must start with letters or underscores and are case sensitive (example: ip1=192.168.2.115)Reference variable: $variable name or ${variable name}View variables: echo $vari ...

1, Overview 1. Concept 1) What is a shell: shell It is a command interpreter, which is at the outermost layer of the operating system. It is responsible for directly talking with the user, interpreting the user's input to the operating system, processing various operating system output results, and outputting them to the screen for feedb ...

Embedded introductory Learning Series notes index 1, Introduction to Linux 2, deb package management 3, Special characters in shell 4, Linux common commands 5, shell programming catalogue 1, shell and variables 1.shell script Basics 2.shell variables 2.1 user defined variables 2.2} position variables (command line parameters) 2.3 p ...

Background: because of work needs, it is necessary to split the data and put it into the table. A total of 64 rows and 8 columns are required. You can't do it manually, so you want to obtain the number of rows first, and then decide how many rows to draw according to the number of rows. However, there is a problem in data acquisition, which has ...

What is a shell? Shell is a program written in C language, which is a bridge for users to use Linux; Shell is not only a command language, but also a programming language; Shell refers to an application that provides an interface through which users can access the services of the Linux kernel Shell scripts include sh, bash, ksh, csh, ...

introduce Under Linux system, the default user root is used There is a script test in the home directory of the remote target machine SH, executable permission. There is only one command: sleep 10 Execute on local machine ssh target "nohup ./test.sh &" As a result, ssh does not exit immediately and waits for test Exit after sh execut ...

catalogue 1. Blog introduction 2. Content . prepare git warehouse . resources for preparing pretreatment . preparing python scripts . prepare shell script . jenkins task creation Implementation of jenkins' mandate . some pits and precautions 3. Push 4. Conclusion 1. Blog introduction This is the fourth and last part of jenkin ...

Ansible fact Ansible is actually a variable that ansible automatically detects on the managed host. The fact contains host related information that can be used like regular variables, conditions, loops in play, or any other statement that depends on the values collected from the managed host. Some of the facts collected for managed hosts may ...

I Format of shell script file shell script file generally consists of three parts: interpreter, command code and comments. [root@server ~]# cat test #!/bin/bash <<notes Here are multiline comments notes echo 'hello world' # Here is a single line comment echo valar morghulis [root@server ~]# sh test hello world valar morghulis The fi ...

1. ls command It is the abbreviation of list. Through ls command, you can not only view the files contained in the linux folder, but also view the file permissions (including directory, folder and file permissions) View directory information, etc. ls -a List all files in the directory, including.Start hidden file ls -A List Division.an ...